EFFECT OF ACTIVE AND PASSIVE SMOKING ON AMPLITUDE OF ACCOMMODATION, NEAR POINT OF CONVERGENCE AND PUPIL SIZE

Abstract

Background:

Smoking is a major risk factor for numerous ocular and systemic diseases. Nicotine exerts significant physiological effects on multiple organ systems, including the eye.

Aim:

This study aimed to evaluate and compare the acute effects of active and passive smoking on pupil size, amplitude of accommodation, and near point of convergence.

Methodology:

A comparative cross-sectional study was conducted at the University of Faisalabad. Thirty participants aged 18–25 years were enrolled after obtaining informed consent. Participants were instructed to abstain from caffeine-containing products and tobacco smoking for 12 hours prior to baseline measurements. Active smokers then smoked a cigarette containing 1.0 mg of nicotine, while passive smokers were exposed to the same cigarette smoke. Pupil size was measured using a pupillary distance ruler, and amplitude of accommodation and near point of convergence were assessed with a Royal Air Force rule five minutes after exposure. Data were recorded on a self-designed proforma and analyzed using paired-sample and independent-sample t-tests in SPSS software.

Results:

Mean ± standard deviation values before and after smoking were as follows: Pupil size: 6.0 ± 0.5252 mm vs. 5.017 ± 0.3592 mm

Amplitude of accommodation: 11.10 ± 0.803 D vs. 9.23 ± 1.194 D

Near point of convergence: 7.03 ± 0.964 cm vs. 8.63 ± 1.066 cm

All changes were statistically significant (p < 0.05; p = 0.00). Pupil size and amplitude of accommodation were similarly affected in active and passive smokers (p = 0.075 and p = 0.093, respectively), whereas near point of convergence was less affected in passive smokers compared with active smokers (p = 0.023).

Conclusion:

Both active and passive smoking produce acute, transient effects on pupil size, amplitude of accommodation, and near point of convergence.

Keywords: Convergence, Nicotine, Pupil, Smoking